Super Best Audio Friends

The evolution of the original irreverent and irrelevant and non-authoritative site for headphone measurements, i.e. frequency response graphs, CSD waterfall plots, subjective gear reviews. Too objective for subjectivists; too subjective for objectivists

A while back, there was a request from some members for me to obtain and test these pads. (As an aside, I have noted the requests and will do my best to get to all of them. Just give me time. And by time, that could be months or even a year!). A shout out to who has helped make this happen. What I have on hard are two versions of the hybrid suede pads. The hybrid pads are wrapped in leather with the surface that rests against the head suede leather. The insides are soft memory foam. One pad looks to be angled, the other is flat. I will compare these to the Drop ESP/95X pads. The Drop pads are velour with a foam which is a slightly stiffer. I find all three pads preferable to that of the stock ESP950 pads. Here are the three sets of pads lined from left to right: Vesper hybrid, Vesper angled, Drop ESP/95X. Note that the ESP/95X pads are mounted on the earcup of the headphone.


Let's start with simple frequency response. Note that the sharp narrow dips in the lower treble and high treble are measurement artifacts (to be confirmed in CSDs in later post.) The Flat Plate Coupler was used here to get the most consistent relative results...
... Anyway, what I wanted wasn't a T2 DIY for the ESP950. I simply wanted an amp which was at least semi-competent with these headphones. There was a BHST (not BHSE) on Head-FI for cheap a few years ago, but I missed out on the opportunity. No way was I going to bother with KGSS or its variants such as HV: macrodynamics and control all right, but talk about flat and boring on the microdynamics plus analytical and sterile - the antithesis of SET. What about STAX? You kidding? I dislike their low-end amps, which are expensive enough already; and kind of dislike their higher end amps. They all sound too soft. Oh, the SRM-T8000? Wow, what a piece of shit for $6k+. I don't know how STAX gets away with making stuff like this. BTW, this review here I totally pulled my punches: What about those STAX energizers? Those made the SR-009 sound like low fidelity headphones, syrupy, non-resolving, goo - and this from the Ragnarok 1, which was otherwise a great small speaker amp if you knew how to get it up right.


This thread documents a comparison of several mid-and-lower-priced headamps I’ve been conducting for several months. The process included both long-term, casual listening to various headamp-phono preamp combos and three shootout sessions, each session featuring a single phono preamp paired against every headamp.


The headamps I compared were: Muffsy MC Head Amp (DIY kit), Lounge Audio Copla, Hagerman Audio Labs Piccolo2, Audio Design MCP-1, Musical Fidelity AC-1, Music Reference RM-4. The first three are current production amps (the Muffsy is a kit), the last three are out of production but are still well considered and available (occasionally) on the used market. Why this comparison and these specific headamps?
This is the PC37X Gaming Headset. There is a new version available as the PC38X which will be covered later. The PC37X is still available. It's on fire sale at Drop for $120. This is part of a series of gaming headset reviews starting here: https://www.superbestaudiofriends.o...gaming-headset-measurements-and-review.11028/


Will follow up with more tomorrow. This headphone also has slanted drivers like the HD560S reviewed here: https://www.superbestaudiofriends.o...560s-review-the-new-standard-not.10040/page-2

The PC37X is in the same class as the HD560S, HD558, HD598 with respect to technicalities (distortion, resolution, etc.) With the slanted drivers like the HD560S, I actually feel the PC37X is the better headphone because the tonality is better. The price is also $80 less. The HD560S does have better bass extension, but it's also brighter, unbearingly so with with its upper mid / lower treble bump.
Measurements and listening impressions of three comparable lightweight, folding, open & semi-open portable units:


Koss PortaPro (left): mfr specs 60 Ohm, 101 dB @ 1mW; familiar to many here. See some discussion here, @Bill-P 's mods and some more discussion here, and @ultrabike 's measurements of a possible fake here. Currently $42 at Amazon US for this grey/blue version.

Sennheiser PX100-II (middle): 32 Ohm, 114 dB (/V?); second version of a design that’s been around a while. Currently $70 at Amazon for the plain-wire version; also available with inline mic/remote.

AKG K-403 (right): 32 Ohm, 118dB/V; discontinued but available from marketplace sellers via Amazon from $34. Semi-open design, bigger drivers (~40 mm) than the other two.

Each of these fold up for transport. The PortaPros have a hook and complementary slot built into the headband to keep them secure, and the K403s have the two-way pivoting-pad design shared by many AKGs. The headband on the PX100-II is in one piece with two pleather pads, whereas the other models have a two-piece sliding arrangement with the K403 having a foam pad under each slider bracket. The Senn is the most comfortable but the AKG feels the most secure on the head thanks partly to the bigger pads/drivers.
It's hard to describe the tonal response of the Sennheiser IE900. At first listen, I couldn't decide whether it was neutralish or U-shaped. There is a peak in the lower/mid treble that emphasizes sibilants and unnaturally sharpens the sound. This peak seems to be narrow, but when it hits, it's very severe. It's most evident on certain recordings that I specifically use to assess this (Alanis Unplugged album, Tom Petty - Don't Do Me Like That). I don't know what it is, but there's something off about it - I cannot listen for more than a song or two before I get fatigued. I would be curious if those who are treble sensitive such as @rhythmdevils or @Hands would notice this. There is also some pinna gain, but not extreme like with IEMs voiced for China. The rest of the upper mids is very slightly muted. While vocals stand out, the trumpet blares on Kind of Blue don't make the hairs on my back stand up as much.


Tonality aside, technically the IE900 is extremely capable. The bass sounds first rate to my ears. There's plenty of it and I found it to be clear, plenty textured, and decently fast. This has to be the best bass in an IEM I've heard in a long while. Could the bass be almost as good as the Sony EX1000? Maybe. It's been a time since I've heard the EX1000 and would be curious to know @Kunlun's thoughts as this could be nostalgia on my part.
The MW10 is an Andromeda through and through. My understanding is that it’s the same 5 balanced armatures, however it was the first Campfire Audio IEM to use the ceramic acoustic 3D printed chamber. The Mix Wave website describes the main change in tuning as mainly the mid-high range but as measurement and impression should show, there is significant difference in bass as well.

Being a limited edition model, the MW10 received its own gorgeous blue color called Strato Blue. The faceplates screws are 24-karate gold-plated and the CA logo is an Avalon inlay, which shows different colors depending on the angle viewed. It really is, arguably, the most beautiful of the Andromeda variants.

Well, probably more measurements than review. @rhythmdevils already covered this here:’s-that-sound-good-and-are-waterproof-to-12-feet-indefinitely.9569/


And I've finally gotten to this months after the fact. Thank you for your patience. The move from CA to TX was big and it took me months to move into a new place and get my measurement gear set up again. Anyway, not only are these IEMs neutralish, but also quite good sounding. Technically much better than their $40 price. The downsides are their rather non-impressive (but waterproof) construction and less than stellar channel matching. However from a clarity point of view, these are very good, better than some IEMs costing thousands and thousands of dollars.

The lower to middle midrange sounds flat to my ears. The lows do sound slightly elevated. Bass texture is surprisingly evident. There isn't much pinna gain built-in, which is fine by me. On the other hand, the 2-3kHz region isn't depressed either. There is a dip around 5kHz (subjective and objective) that takes the edge off of snare drums and bite out of trumpets. The lower and mid treble are about right, but high treble, last octave air is missing. I really cannot complain for $40. Besides many single driver DD IEMs, even some high-end ones, lack air as well.
The HE400se is a really nice addition to the entry level headphone market. The other being the Drop x HFM HE5XX which received a ton of controversy because some people felt that it didn't live up to the original HE-500 (ignoring the fact that the HE5XX cost $500 less than the HE-500). Both the HE400se and HE5XX are on my list as the more pleasant sounding entry level headphones from HFM without any (much) upper-mid or lower treble peaks. The HE400se is on the more neutral sounding side, the HE5XX is darker.

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Being an entry level headphone, the HE400se isn't what I would call super resolving. There's a bit of macro-detail, increased definition, maybe even "fake" detail or sharpening effect because of the mid-treble 10kHz peak (similar to the HE5XX). The transients are not as zippy or tight as high-end planars. The headstage in nothing spectacular. It's close, compact, but with decent width. The bass extends well, with a shallow slope down toward 20Hz instead of suddenly taking a sudden dump like many open back dynamic headphones.
The RSV is in the ballpark of reference neutral, however I do find it on the warm and smooth side of that description. To me this is a good thing, it makes it effortlessly listenable but could be disappointing to those looking for the ultimate neutral reference. At any rate, deep and sub bass are boosted over neutral. For the most part, the boost is natural and tastefully done. At times, it can be hair heavy handed for my personal preferences. The midrange is clear, transparent and balanced, all while being easy to listen to. Treble is every so slightly shelved down from neutral. There isn’t anything harsh or remotely bright sounding about the RSV with stock tips. While the RSV doesn’t inherently add any warmth, the slightly boosted sub bass and the slightly shelved treble make for an overall warm and smooth signature that doesn’t stray far from neutral. For someone like me, who prefers a neutral/reference signature, this is my relaxed and pleasant approach. It's just so pleasant and listenable without being overtly colored.


Bass on the RSV is slightly more elevated in deep and sub bass over the Blessing 2. The amount isn’t all that large but it lends to a more natural and palpable bass, despite the fact the RSV is armature bass. In fact, I’d say the RSV bass also presents better texturing down low, as the Blessing 2, while dynamic driver based, has bit of an overdamped, muted texture. Listening to electronic music or double bass metal, the RSV is able to deliver a more engaging and dynamic rumble.
These headphones were very difficult for me to get consistent results with. I was able to get a better seal a few days ago, but it seems that I could not replicate the result today no matter how hard I tried. I spent maybe 20 minutes readjusting, fluffling the pads, but I could not get better bass extension than this.


Here is a photo of of the earcup, swivel mechanism, and part of the headband. The construction is cheap but serviceable. I have no idea of the robustness of the design, only time will tell. For $40, that's what we are gonna get through. I was able to get my ears just into the cups. My ears touch a bit so it's slightly uncomfortable, but not overbearingly so. Those with larger ears should definitely skip this model. It looks look like Turtle Beach has won the race to the bottom. I thought they were supposed to be a high-end brand, but that was 25 years ago.
FiR Audio, a relatively new in-ear manufacturer, was founded in 2018 and released their first in-ears in 2019. However, the man behind it, Bogdan Belonozhko, was previously part of 64 Audio (and previously 1964 Ears). I haven’t had opportunity to hear any other models from FiR, so the VxV will the first. Fir Audio graciously provided the unit for review.


The VxV (or 5x5), coming in at a price tag of $999, is one of the cheaper models in the FiR lineup and was recently on Drop for $799. It looks like the VxV is the only one in the lineup that only comes as a universal. Apparently it is a limited run but I’m unsure of the number of units that will be made. The VxV consists of a 6.8mm dynamic driver and 4 balanced armatures: 2 for midrange, 1 for treble and 1 for super-high frequencies. The VxV is equipped with a pressure releasing vent system. Rather than being placed on the faceplate, its tucked away under the cable connector near the top of the housing. As far as I know, these aren’t user replaceable like the larger faceplate mounted options in 64 Audio in-ears. The 2 treble armatures are spoutless and I assume are positioned inside the housing bore, as described on FiR’s TECH page: